He reads the parable of the workers in the vineyard eschatologically. It is a story about the last times, and of our eternal fate. The "evening" of the parable is the Day of Judgment, and he depicts it as a brief history of salvation:
The first righteous men, as Abel, and [Noah], called as it were at the first hour, will receive together with us the blessedness of the resurrection.
Other righteous men after them, Abraham, Isaac, Jacob, and all of their age, called as it were at the third hour, will receive together with us the blessedness of the resurrection.
Other righteous men, as Moses, and Aaron, and whosoever with them were called as it were at the sixth hour, will receive together with us the blessedness of the resurrection.
After them the Holy Prophets, called as it were at the ninth hour, will receive together with us the same blessedness.
In the end of the world all Christians, called as it were at the eleventh hour, will receive with the rest the blessedness of that resurrection.
Even though Augustine has already, and somewhat blithely, mentioned that the Jews have lost their reward for rejecting Jesus, here he lines up a bunch of Old Testament figures and sends them straight to Heaven, with no limbus patrum to worry about. Christians, humbly, are added on last.
This is noteworthy. Preachers often turn this parable into "lifers" versus "converts," or even "longtime members versus new members," which is a message some churches need to hear. And Augustine talks about this reading as well:
[Some] were called at the first hour, who begin to be Christians fresh from their mother's womb; boys are called as it were at the third, young men at the sixth, they who are verging toward old age, at the ninth hour, and they who are called as if at the eleventh hour, are they who are altogether decrepit; yet all these are to receive the one and the same denarius of eternal life.
But his first distinction is between the community of the Old Testament on one hand, and that of the New on the other. And for Augustine, we Christians are all the new members. All Christians are late to the table, all Christians are eleventh-hour hires, all Christians deserve (by human thinking) less than those who came before.
He goes on an excursion (which may belong to some other sermon), talking about
[T]wo things [that] are the death of souls: despair, and perverse hope. For as a good and right hope saves, so does a perverse hope deceive.
We mentioned Luther's White Devil the other day, a clever nickname for the perverse hope which makes a person think that something evil is actually righteous. This may be useful for some sermons.
But then Augustine hits on something that most of us in the Pauline tradition have to deal with: the moral hazard of grace. You know -- spiritual laziness, the "I can sin a little bit now, and be forgiven later, and still go to heaven with the saints." That is, surely, one way of reading the parable; and as we all know, it was a popular one in some quarters. Government bigwigs would put off their baptism until they retired, or even lay on their deathbeds, so that they could launch as many wars or kill as many prisoners as they wanted, and have it all washed away at the end.
Augustine attacks the problem from several angles. For example, he says, don't claim that you have not yet been called; Christ is nowadays known and preached everywhere, and that preaching calls you. To pretend otherwise is to wilfully reject Christ. People do reject him, of course; usually either in a frenzy or in a torpor, out of rage or out of laziness.
Frenzy and torpor are both symptoms of an illness. When you are sick, says Augustine, you go to the physician, right?
The Incarnation is a house-call? Sweet. Then come examples of Christ healing the people whose symptoms are frenzy: Saul, of course; the first persecutors, some of whom changed their hearts afterward, so that "they were converted to Him whom they crucified, and as believers drunk in the Sacrament His Blood, which in their violence they shed."
And then, at last this:
And so again many lethargic ones are healed. For to such are they like, who are not violent against Christ, nor malicious against Christians, but who in their delay are only dull and heavy with drowsy words, are slow to open their eyes to the light, and are annoyed with those who would arouse them.Get away from me,says the heavy, lethargic man,I pray you, get away from me.Why?I wish to sleep.But you will die in consequence. He through love of sleep will answer,I wish to die.And Love from above calls outI do not wish it.
Just read the last bit over a few times: Ille amore somni, Mori volo, respondet. Et caritas desuper: Nolo. Gives you the shivers, dunnit?